Piston ring



Patented Nov. 18, 1924.

UNITED STATES PA-TENT OFFICE.

JOHN E. BROWNFIELD, or DENVER, COLORADO, ASSIGNOR on ONE-HALF TO JOHN G.

. JONES, or DENVER, COLORADO.

PISTON RING.

Appflication filed April 5,

To a whom it may concern:

Be it known that 1, JOHN E. BROWNFIELD, a citizen of the United States,residing at Denver, in the city and county of Denver and State ofColorado, have invented certain new and useful Improvements in PistonRings; and I do declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and r use the same, reference beinghad to the accompanying drawings, and to the characters of referencemarked thereon, which form a part of this specification.

This invention relates to improvements in piston rings.

In all types of engines employing reciprocating pistons, it is essentialthat there shall be a gasand oil-tight fit between the pistons and thecylinder walls. This tight fit must be obtained without the productionof an undue amount of friction. In the ordinary internal combustion ewine, such as. is extensively employed on automobiles, the pistons areformed with grooves for the reception of piston rings, which areresilient and engage the inner surface of the cylinder. As these ringsfit rather loosely in the grooves on the piston, they do not form agas-tight and oil-tight seal, but permit considerable leakage to takeplace. I am aware that many different expedients have been resortedtTif0f-thQ4Jl1ljPOSO of making a tight seal between the cylinder wallsand the piston, some of which have'been employed with some degree ofsuccess.

It is the object of this invention to produce a piston ring that can beemployed with any standard piston and which shall be so constructed thatit will permit a peculiarly shaped spring member to be inserted be tweenthe bottom of the groove in the piston and the inner surfaceof the ring,for the purpose of producing a uniformly distributed force tending -tomove the ring outwardly against the inner surface of the cylinder and,at the same time, form a seal be tween the ring and the piston.

My invention can be most clearly ex plained and will be most readilyunderstood when reference is had to the accompanying drawing in which myimproved construction is illustrated, and in which:

Fig. 1 is a View partly in section and partly in elevation of a pistonand a cylin- 1924. Serial No. 704,413.

der, parts being broken away to better show the construction of thepiston ring;

Fig. 2 is a section taken on line 22, Fig. 1, the parts being shown toan enlarged scale;

' Fig. 3 is a perspective View of a portion of the spring ring; and

Fig. 4; is a section taken on line i4, Fig. 3.

Numeral 1 indicates the cylinder and 2 the piston, which is providedwith a plurality of grooves 3 for the reception of the piston rings at.The rings differ from the ordinary piston ring only in one particular,namely, in that a portion of the inner surface has been cut away to forman offset 5. This offset extends substantially one-half of the width ofthe ring, in the manner shown in the drawings. For the purpose ofproducing a force that tends to expand the pis ton ring, I have provideda spring having a portion 6 bent into circular form and adapted to liesnugly against the bottom of the width of the groove 3. The sides 6 and7 are normally inclined to each other at an angle substantially likethat shown in Fig. 4, but when the spring ring is in the piston ringgroove and the ring is within the cylinder, the sides 6 and 7 are forcedinto a more nearly parallel position, such as shown in Fig. 2. hen thesides 6 and 7 are moved to the position shown in connection with thelower ring in Fig. 2, the cuts 8 are almost, if not entirely closed. Theside 6 fits snugly against the bottom of the piston ring groove and theside 7 fits against the inside of the piston ring. It is now apparentthat the spring'ring forms a seal between the piston and the ring. Sincethe cuts 8 are substantially closed, any oil that enters the groove andcomes between sides 6 and 7 will help to make the seal perfectly tight.The spring fingers 7 act uniformly on the ring to spread the same apartand therefore produces a uniform force tending to force the piston ringagainst the side of the cylinder. This force is suilicicnt to cause thering to lit the cylinder, even when the latter has been worn so that itis no longer exactly circular. The spring ring, in addition to forming aseal, also prevents side slapof the piston and permits the ring to beworn to a far greater extent than would otherwise be practical. Thematerial of which the spring ring is made is preferably spring steel,although other resilient material may be employed. I contemplate, usingmaterial. about one one-hundredth of an inch in thickness, in which casethe material should be cut away from the inside of the ring to a depthof about three one-hundredths of an inch.

Having now described my invention, What I'claim as new is:

1. In. combination, a cylinder having a piston ring groove ofsubstantially rectangular cross-section, a ring-shaped spring member insaid groove, said member having a substantially V-shaped cross-section,and a ring in saidgroove, said rin having onehalf of its inner surfaceoffset rom the other half thereof, whereby space is" provided for thespring member.

2. In combination, a cylinder having a substantially piston ring grooveof substantially rectangular cross-section, a ring-shaped spring memberin said groove, said member having a V-shaped cross-section, the outerportion of said ring being cut so as to provide a plurality of adjacentfingers,

and a piston ring in said groove, the inner surface of said ring havinga portion thereof offset so as to provide space for the spring ringmember.

3. In combination, a cylinder having a lar cross-section, a ring-shapedspring member in said groove, said member having a JOHN E. BROWNFIELD.

piston ring groove of substantially rectangu-

